Incandescent lamp.



M. M. MERRITT.

. INGANDESOENT LAMP. APPLICATION FILED NOV. 27. 1905.w

1,062,836. v Patented May 27, 1913.

UNITED STATES PA TENT OFFICE.

MATTHEW M. MERRIT, 0F MIDDLETON, MASSACHUSETTS, ASSIGNOR, BY MESNEASSIGNMENTS, TO GENERAL ELECTRIPC COMPANY, A CORPORATION OF NEW YORK.

INCANDESCENT LAMP.

Specification of Letters Patent.

Patented May 27, 1913.

To all whom it may concern:

Be it known that I, MATTHEW M. MER- nrr'r, a citizen of the UnitedStates, residing at Middleton, in the county of Essex and State ofMassachusetts, have invented an rnprovement in Incandescent Lamps, oi'which the following description, in 4connection with the accompanyingdrawings, is a specification, like letters o-n the drawings representinglike' parts.

My invention yrelates to incandescent lamps and more particularly tomethods of and means for anchoring or ,supporting the filaments therein.

My invention will be best understood by reference to the followingdescription taken in connection with the accompanying illustration oione specific embodiment thereof, While its scope will be moreparticularly pointed ont in the appended claims.

Referring to the drawings,-Figure l shows a lamp provided with afilament which requires support at a.`plurality of points intermediateits ends, the same being anchored, according to the one embodiment of myinvention which is submitted to illustrate the principles thereof; Fig.2 shows on an enlarged scale the anchor carrying sleeve with its twoconnections or supports employed in that forni of Amy inventionillustrated in Fig. l, the sam-e being secured to a supporting wire byone method; and Fig. 3 shows the same secured to f id wire by anothermethod.

Referring to the drawings and particularly to Fig. l, I have there showna lamp having a filament for which, on account of its length and shape,involving as it does a `plurality of coils or loops, it is desirable toprovide anchor supports d, at a plurality of points, intermediate itsends. It will of course be understood that this form of filament isillustrative only 'and it will be ob- `v'ious, as is hereafter moreparticularly set forth, thatmy invention has useful application towidely didering forms and construcupright anchor wire sealed at yone endinto the stem ,of the lamp, midway between the ends of the filament andconnected atv its opposits end to the nearest portion of the filamentloop.

In lamps of the type shown in Fig. 1, which has a double coil filamentsuch as is typical for instance of a Q20 volt lamp, the single anchorsupport of the single coil lamp has ordinarily been duplicated, the twosupporting wires being individually, except as to location and perhapsvdimensions, substantially the same construction as the single supportingwire of the 110 volt lamp.

The employment of a plurality of anchorv wires sealed into the stem of alamp although heretofore deemed desirable and for many forms-offilaments necessary, has been found to possess several disadvantages.For example, the sealing-in of two anchor wires instead of one increasesthe chance of breakage and consequent leakage, for the supporting wiresd, l become highly heated through-their connection with the filament andtend to crack the glass` where joined thereto. This is evidenced inactuzil practice by the large percentage of lamps which under usage 'arecracked or broken at the end ofthe stem. Moreover, a speciallyconstructed stem, that is, one provided with a pair oanchor wires sealedtherein, must ordinarily be provided fora multi-coil lilament and adiderent one, that is, one having By the use of my invention whencarried i .out as in the described embodiment, the chances of breakagefrom the connectionbetween the ancho-r support and the stem are reducedto a minimum, While still providingaplurality of points of anchorattachment for the ilament; moreover, if desired, substantially the sameconstruction of stem may be employed for either a single-coil ormulticoil filament, and, Whether on the installation of the filamentY inthe rst place or on the renewal thereof, thevl same lamp-base,

stem and globe may be used interchangeably with either type of'filament. It may also be possible to anchor the filament not only in twobut in three, fouror any number of points in the length thereof, if, forany rcason, such anchoring seems desirable.

In Fig. l, where I have sho-wn for illustrative purposes one embodimentof my invention, the loops Z1, Z) of the filament c are anchored at theusual points, but by means of the. two separate anchor supports, fl, CZconnected to the single anchor support e, the latter scaled in orotherwise suitably secured to the stem f of the lamp. The support emaybe of any suitable material or shape, but the same preferably, asshown, consists of a single wire support sealed into the sternintermediate the filament ends, and preferablyfas is ordinarily done inconnection with single-coil filaments.

rIhe branch Wires or supports (Z, d, which should be electricallyseparated to prevent short circuiting the intervening portion ot thefilament, may be connected to the support e in any suitable way7 but forconstructional advantages, and to permit itsready application andmanipulation with reference to a` lamp having a previously sealed-inanchor wire,l prefertoattach them to a perforated or otherwise formedinsulating body such as the insulating sleeve g, which may readily beengaged lwith and attached to the anchor wire e. "lhe sleeve y; may be,and preferably is, a picco of' small glass tubing, into the sides ofwhich the inturned ends of the supports' al, d, may be welded by merelysoftening the sides of the tube in the blow pipe flame, this providingat the same time a firm and efficient cmincction and presenting aninsulating body between the ends of the wires.

In the renewal of a lamp, for example, an aperture may first be formedin thev tip end of the bulb opposite the stem; as is usual, and thesleeve or anchor carrier g with its attached connections, when formed-as de` scribed and as-shown in Fig. i2, may be entered through theopening and `slipped over the end ot the anchor wire To this it may besecured either fixedly in any suitable Way, as by welding the end ofithe .same to the single anchor wire, (sce Fig. 2) or it may be'somcwhatloosely attached thereto, as by bending over the projecting upper tip ofthe anchor wire c (see Fig. 3) to prevent escape of the sleevetherefrom, while permitting more or less movement of' the sleevelengthwise on the upright support.

Thilo the welding or other mode of xcdly attaching the anchor carrier tothe Sealed-in support may be preferable in many instances, that mode otfastening which permits some degree of play between the sleeve and thehor wire is arlaiitageo1is and particularly so with certain filament-s,such for instance as large filaments, for the sleeve is then permittedto follow more or less the expansion and contraction of the lamentJwithout straining the same, as might occur were. the anchor wireperfectly' rigid, and less heat is conducted to thc sealed-in wire. Thelamp having been prepared by the insertion of the anchor wires asdescribed, the filament may then be installed in the usual way.

Not only does the use et' a single anchor support of itself decrease thechances ot breakage at the point where the anchor wire is sealed intothe stem, but, where my invention is carried out. in some way similar tothe specific one illustrated, the carrier g acts, not merely as aneffective radiator of heat conducted from the filan'ient thereto,causingl such heat to be dissipated before it reaches the junction ofthe anchor wire and the stem, but, when formed separate from the anchorwire, and particularly when loosely mounted thereon, the carrier has aheat insulating space between it and the anchor support, all thistending to prevent the deleterious effect of the heat transmitted fromthe tilai'nent to or toward the stem.

My invention is especially advantageous in its bearing upon the renewingof lain; that is, the replacing of a burned ont o otherwise damagedfilament by a 'fresh fila ment through a small opening made or thatpurpose in the tip of the lamp bulli.

By the use of my invention the manufacturer of renewed lamps may, ifdesired,

place a filament requiring a l'ilurality of anchor supports 1n a lampthat was originally made with but one anchor wire or lilament support,the only addition necessary vchor carrier with its previously attachedwires, being perforated, is readily placed on and over the projectingsealed-in wire, with an case which is desirable where the manipulationmust be carried on through the small restricted opening in the end otthe lamp bulb. One advantage possessed by a sleeve in this operation isthat it brings the ends. of the anchor support at a previouslyascertainable position so that no fitting need be done after the supportis in position. Through the use of this invention, therefore, themanufacturer of renewed lamps is required to keep in stock old ordamaged lamps of but one style, namely, those having the single filamentsupport.. These may be renewed into lamps having` either vthe singlefilament or the double filament support..

4The present manufacturing practice lies in the direction of filamentsdesigned with llt) incassa a view to eifectivelight radiation and ofsuch form, shape and construction as to require, or make highlydesirable,`a plurality of anchor supports. It therefore follows that, ina lamp provided with a filament constructed perhaps according to earlierusages in the art and having relatively iny erior light-distributingqualities, my invenp an tion permits the substitution for that, tila`ment, Whether the latter is impaired through usage, or. nnimpaired, of anew lainent of superior lightdistributing qualities for which two ormore anchor supportsiare desirable or necessary7 thus, in effectconvert` ing an interior lamp into a superior one.

ll'hile l have disclosed and described in detail one embodiment of myinvention -suii- -cient to give an adequate comprehension thereof, it isto be understood that the same includes Within its scope extensivemodifi cations thereof and wide departures therefrom and many variationsin construction and manipulation which will be obvious to Athose skilledin the art7 all of which are unnecessary for me to refer to or suggestherein. v

Claim:

l. )in incandescent lamp provided with a filament, a stern through whichthe filament connections enter, a single metallic anchor wire sealedinto said stem, a glass sleeve upon said wire, and electri rally sepa-:rated branch wires sealed into said sleeve and connected respectivelyto different points in the length of said 'filament Q. An incandescentlan'lp provided with l a'tilainent, a stein, a single metallic anchor Alt) sleeve and connected respectively to difterent points in the lengthvof said filament. 4 3. An incandescent lamp having a tila ment7 a stein,a metallic anchor support sealed into said stem, a perforated body ofinsulating material secured to said support, and a plurality ofelectrically separated anchor Wires secured to said insulating materialand at their opposite ends connected respect-ively to dierent points inthe length of the filament.

4. The combination with a lurality of tilament loops of a metallic ancior support and -a plurality of electrically separated supports by whichthe various ilament` loops are supported and which are connected to saidanchor support by a perforated carrier movably mounted thereon.

5. An anchor carrier for an incandescent lamp comprising a hollowelongated sleeve adapted to be placed upon a filament supsport. and aplurality of. electrically sepa` rated connections secured to saidsleeve and adapted to be attached to` separated'points in the length ofthe lamp filament.

(l. An anchor support for a lamp filament comprising an elongatedsupporting member adapted for attachment to the lamp7V said member beingperforated for applica` tion to a suitable projecting,- part on the lampand separate, anchoring supports secured to said member.

In testimony whereof, l havesigned my name to this specification, in thepresence of two subscribing witnesses.

ltit'lTllEW M. MERRlT Witnesses THOMAS li. Boo'rii, Citas. E. lhnncn.

